/* cat.c

Copies one file to another. */

#include <stdio.h>
#include <syscall.h>

int main(int argc, char *argv[])
{
    int in_fd, out_fd;

    if (argc != 3)
    {
        printf("usage: cp OLD NEW\n");
        return EXIT_FAILURE;
    }

    /* Open input file. */
    in_fd = open(argv[1]);
    if (in_fd < 0)
    {
        printf("%s: open failed\n", argv[1]);
        return EXIT_FAILURE;
    }

    /* Create and open output file. */
    if (!create(argv[2], filesize(in_fd)))
    {
        printf("%s: create failed\n", argv[2]);
        return EXIT_FAILURE;
    }
    out_fd = open(argv[2]);
    if (out_fd < 0)
    {
        printf("%s: open failed\n", argv[2]);
        return EXIT_FAILURE;
    }

    /* Copy data. */
    for (;;)
    {
        char buffer[1024];
        int bytes_read = read(in_fd, buffer, sizeof buffer);
        if (bytes_read == 0)
            break;
        if (write(out_fd, buffer, bytes_read) != bytes_read)
        {
            printf("%s: write failed\n", argv[2]);
            return EXIT_FAILURE;
        }
    }

    return EXIT_SUCCESS;
}
